The gauge refers to a borderline that is not allowed to be exceeded by locomotives and buildings and equipment close to a track line in order to ensure safety of the locomotives operating on the track line and prevent the locomotives from colliding with the buildings and equipment close to the track line. During long-term operations of a train on the track line, there may be situations where the train body is out of shape or a cable on the train roof falls down. When the train is operating in such situations, a part of the train out of the gauge may easily collide with or hook surrounding objects, which may cause hidden risks in the operation of the train. Here, the out-of-gauge part refers to an area beyond the gauge due to causes such as a protruding deformation of the train body or the falling down of the roof cable. Therefore, it is necessary to perform a gauge detection for a metro vehicle when the metro vehicle gets in-storage or out-of-storage, so as to ensure that the vehicle has no safety risk.
At present, most metro vehicles need to perform a return operation after completing an operating task. That is, a dispatcher will transfer the vehicles to a depot in sequence. Currently, the Communication Based Train Control. System (CBTC) does not have the capability of gauge detection. The details of each vehicle are mostly confirmed by a driver or a ground maintenance personnel after the vehicle returns to the depot. Due to poor working environment, working hours and other reasons, inspectors may have problems such as lack of concentration, easy to sleepy, and difficulty in distinguishing subtle errors during the inspection for the returned vehicles, and thus the inspection may be unstable because of different conditions of the inspectors. Therefore, the inspection conducted by the inspectors for the vehicles to be in-storage or out-of-storage may have low efficiency of gauge detection.